Bupivacaine Pharmacokinetics Following TAP Block

"Bupivacaine levels will be measured with an assay developed on the 4000 QTrap Tandem Mass Spectrometer (Applied Biosystems/ MDS Sciex).~Data will be collected and analyzed using the Agilent ChemStation software (Rev A.10.02). The analytical column is an Agilent Zorbax Eclipse XDB-C8 (4.6 x 150mm, 5µm).Quantification of bupivacaine is based on analyzing a six point calibration curve (0 to 4.0 mg/L). An internal standard (Prilocaine 221.2/86.1) is included with each calibrator, quality control or patient sample. Instrumentation and Chromatographic conditions: The HPLC system consists of a Specta-System P1000 Isocratic Pump and an AS3000 Autosampler (Thermo Electron Corporation, Waltham MA)."